Fish is a healthy protein source rich in omega-3 fatty acids, which support brain health, reduce inflammation, and may lower the risk of chronic diseases. However, some fish carry health or environmental risks that make them worth avoiding.

Mercury pollution from industry enters waterways and accumulates in the marine food chain. Larger predator fish often have the highest mercury levels, posing risks like mercury poisoning. Agencies such as the FDA, EPA, and EDF provide consumption guidelines.

Tilapia, while popular, is high in inflammatory omega-6s and low in omega-3s. If consumed, choose wild-caught or responsibly farmed sources from the U.S., Canada, or select countries.

Overfishing has depleted Atlantic cod and Atlantic flatfish (halibut, flounder, sole). Caviar from sturgeon, Chilean bass, and eel also raise concerns — from high mercury to critical endangerment. Eel in particular absorbs pollutants easily.

Imported basa, swai, and striped catfish may carry harmful bacteria, while imported farmed shrimp often contains banned pesticides and antibiotics. Imported king crab is often mislabeled and may come from unsustainable fisheries.

Other high-mercury or overfished species include orange roughy, shark, Atlantic bluefin tuna, swordfish, king mackerel, and grouper. Some, like grouper, are also frequent victims of seafood fraud.

While selenium in certain fish can offset mercury absorption, it’s not a license to eat high-mercury species regularly. Sharks, for example, have high mercury and low selenium — a risky mix.

Safer, sustainable alternatives include wild-caught Alaskan salmon, Pacific sardines, Atlantic mackerel, U.S./Canada-caught albacore tuna, Alaska cod, Arctic char, and rainbow trout. The EDF Seafood Selector offers guidance for healthier, eco-friendly choices.